Rocks

Flint is sedimentary rock with a fine, compact texture and a shiny fracture. This piece of gray flin...

Flint splits in any direction and fractures into sharp edges, which made it a good material for preh...

Flint is a sedimentary form of silica, often found in limestone. This rock contains a core of black...

Limestone and red flint sandwich, 4 cm long. Photograph by Peter B Tzannes, 2004

These wonderful beach stones are made from layered bands of black flint and white almond stone. The...

This is a conglomerate in which the fragments are not rounded, but sharp and angular. This one is 8...

Conglomerate rock, containing rounded bits of other rocks, 5 cm long, found on Paliopoli beach. Phot...

Metamorphic rock formed from shale or mud, containing sparkling minerals of mica. This specimen, fou...

A small piece of Gneiss, 4 cm long, showing its coarse grain. Photograph by Peter B Tzannes, 2004

Metamorphic, coarse-grained rock, often banded. This specimen, showing where the rock has been folde...

Metamorphic rock with a hard, compact texture, which may contain dead organic matter and lead. This...

This incredible beach stone has veins that spell the Greek word ‘oxi’, meaning ‘no.’ Imagine our ama...

Beach stone illustrating Euclidean proposition VI.2. Photograph by Peter B Tzannes, 2004

Beach stone illustrating the Euclidean diagram for Book One, Proposition 27. Photograph by Peter B T...

Beach stone with the number 70 inlaid in calcite. Photograph by Peter B Tzannes, 2004

Beach stone inscribed XVI, the Roman Numeral for 16. Photograph by Peter B Tzannes, 2004